1. Field of the Invention
The present invention relates to a power converter that converts input voltage and outputs the converted voltage by turning ON and OFF a switching element.
2. Description of the Related Art
Conventionally, for example, a power conversion system disclose in JP-A-2009-131067 is known as a power converter that converts input voltage and outputs the converted voltage by turning ON and OFF a switching element.
The power conversion system includes a power conversion circuit, a voltage sensor, a current sensor, and a control circuit. The power conversion circuit has a switching element, and converts input voltage and outputs the converted voltage by turning ON and OFF the switching element. The voltage sensor is connected to a control calculating section of the control circuit as a means for detecting input voltage and output voltage of the power conversion circuit. The current sensor is connected to the control calculating section as a means for detecting output current of the power conversion circuit. The control calculating section controls the switching element by outputting a pulse width modulation (PWM) signal for turning ON and OFF the switching element, based on the input and output voltages detected by the voltage sensor and the output current detected by the current sensor.
For example, when a disconnection occurs between the voltage sensor that detects the output voltage of the power conversion circuit and the control calculating section within the control circuit, the control calculating section judges that the output voltage has dropped and suddenly increases the duty ratio of the PWM signal. Therefore, until the disconnection is detected, the output voltage on a secondary side of the power conversion circuit temporarily rises. Therefore, the power conversion circuit is required to be configured using components having sufficient withstand voltage that take into consideration temporary rise in output voltage, such as that described above, on the secondary side and a circuit connected to the secondary side. A problem occurs in that cost increases.